Compression type refrigerating system



Jan. 3, 1933.. P. w. DES ROCHES COMPRESSION TYPE REFRIGERAIING SYSTBI Filed Sept 9. 1927 Patented Jan. 3, 1933 UNITED STATES PHILIP W. DES ROGHES,

OF DETROIT, MICHIGAN COMPRESSION TYPE REFIHGERATING SYSTEM Application filed September 9, 1927. Serial No. 218,396.

My invention has for its object to provide a new and eflicient refrigeratingapparatus wherein any of the well known refrigerants may be used, such as, sulphur dioxide, butane,

or methyl chloride, and yet wherein the deleterious effects of the lubricant passing from the compressor into the cooling system may be eliminated. The invention particularly provides for the continuous separation of the O lubricant from the refrigerant during the cyclic operations of the apparatus and insures a continuous control of the circulation of the lubricant and the refrigerant.

Any suitable lubricant may be used for lubricating the compressor, such as oil, or glycerine. As is well known the lubricant continually mixes with the refrigerant and is carrried from the compressor into other parts of the system. Certain refrigerants are heavier than the lubricant used and others are lighter than the lubricant and still others mix with or dissolve the lubricant in varying degrees. By my invention I provide for the continuous separation of the lubricant from any one of the refrigerants by the evaporation, or distillation, of the refrigerant so that the lubricantthat is thus separated from the refrigerant may perform its lubricating function when it is returned, with the refrigerant vapor to the compressor. Thus, by my invention, the lubricant is continuously removed from the refrigerant which enables the refrigerant to efiiciently perform its function of chilling a refrigerator, or other object, or material, according to the use to which the apparatus is put. By the continuous separation of the lubricant from the refrigerant, supercharge, or over dilution, of the refrigerant with the lubricant, is prevented and the compressor is never starved of its lubricant supply.

\Vhere anhydrous sulphur dioxide is used as the refrigerant the lubricant commonly used will float on the surface of the liquefied sulphur dioxide, while in the case of methyl chloride, some lubricants will sink to the bottom of the liquefied chloride. On the other hand, where the lubricant is partially K0 or completely dissolved as in butane, it is u gradually concentrated and separated by the evaporation of the refrigerant in the system. It may be separated out as the refrigerant produces its function ofchilling in the refrigerating apparatus. Where glycerine is used, there is more or less dissolution in the refrigerant and it also is separated out by distillation.

A further object of the invention is to provide for the uniform deposition of the lubricant in the return stream of the refrigerant vapor to the compressor in order to avoid a surfeiting of the lubricant in the return pipes of the refrigerant, particularly during that period in which the compressor ceases its operation and provides a greatly improved means for distilling the refrigerant liquid from the lubricant in the refrigerating portion of the system whereby the evaporation of the refrigerant may perform its chilling function usefully. A further purpose of the invention is to provide means whereby the ready passage of appreciable volumes of liquid to the compressor is brought under control. This makes the refrigerating system safer to use and protects the compressor against injury. The invention provides these above mentioned advantages regardless of the character of the refrigerant or the lubricant, whether the latter floats on top of, dissolves in, or sinks to the bottom of the refrigerant liquid. The system operates periodically and cyclically so as to produce condensation of the refrigerant to a liquid and then allows the liquid to evaporate and accumulate as a gas in the apparatus as heat is absorbed from the medium which is associated with the apparatus. Thus by my invention I have provided a uniform rate of lubricant movement to the compressor when it is in operation, notwithstanding the periodic character of the system.

My invention may be embodied in various types of refrigerating systems and, to illustrate a practical application of my invention, I have selected a system containing the invention as an example of the various systems embodying my invention, and shall describe the system selected hereinafter. The

system referred to is shown in the accompanying drawing.

Fig. 1 is a diagrammatic illustration of the refrigerating system selected as an OK- ample, and illustrates parts of the apparatus in section and part in elevation. Fig. 2 is an enlarged View of a lubricant remover that is located at one point of the circuit of the refrigerant. Fig. 3 is an illustration of a modified form of the oil remover shown in Fig. 2. Fig. 4 is an enlarged view of one of the valves located in the system for in creasing the ability of the apparatus to distill off the liquid refrigerant from the lubricant.

The system is provided with the usual compressor 1. which is driven by a suitable motor 2. The refrigerating liquid as it is compressed leaves the compressor as a gas at high pressure and passes into the condenser coils which may be air or water cooled. As the gaseous refrigerant is cooled. it condenses to a liquid and moves downward in the coil and enters the chamber 4 until the level of the liquid in the chamber 4 is high enough to open the float valve 5. The float valve 5 may be made of any suitable form of float valve which is controlled according to the level of the liquid in the chamber 4, and so as to maintain a certain amount of liquid within the chamber. The liquid flows through the tube 6 into the container 7 when the valve 5 is opened.

As is well known in connection with compressor systems heretofore used in the art, the pumps that operate to compress the refrigerant require free flowing lubrication on account of the characteristics of the refrigerantthat is used with the result that there is introduced into the refrigerant a proportion of lubricant which is carried into the refrigerating circuit of the apparatus. Different means have been provided for eliminating the lubricant from the refrigerant, but, nevertheless, in apparatuses heretofore used, there is constant accumulation of the lubricant quantity which gradually lowers the efficiency of the refrigerant. Eventually the refrigerant becomes surcharged with the hibricant and fails to perform its function. By my invention I have provided means whereby the lubricant is progressively and continuously separated from the refrigerant as fast as the refrigerant performs its chilling function and, although the lubricant is delivered into the refrigerant stream on its return to the compressor, the refrigerant does not become surcharged with the lubricant and the lubricant that is thus returned etiiciently performs its function of lubricating the compressor. Thus by my invention the lubrication of the (.OITIPIGSSOI is maintained. although the lubricant is being drawn from and forced into the refrigerating apparatus in the manner well known in the art. In the chamber 4 the lubricant has its first opportunity to become separated from the refrigerant, if it has a greater specific gravity than the refrigerant and is not readilysoluble therein, since the refrigerant is there reduced to a liquid. If the refrigerant is of such a character that it is heavier than the lubricant, the lubricant will collect on the surface of the liquid that is formed in the chamber 4. \Vhere the conditions are such that the lubricant floats on the surface of the liquefied refrigerant in the chamber 4, it will be washed through by the continuously moving liquid and where the lubricant is dissolved by the liquefied refrigerant, it will be likewise carried through the chamber. The lubricant is indicated in the particular structure shown as being heavier than the liquefied refrigerant and. therefore, portions of it contained in the refrigerant settles to the bottom of the chamber 4.

The outlet pipe 6 of the chamber 4 is connected to the refrigerant liquid container 7 which is located in the refrigerator or in the medium that is to be chilled by the refrigerating apparatus.

The liquid when flowing into the container 7, enters the low pressure side of the system where, by its gradual evaporation, heat is absorbed from the surrounding medium and the refrigerant produces its function of chilling. Vhen the liquid enters the container 7, it is given opportunity to evaporate because of the low pressure, and the vapor passes from the container 7 through the other units of the refrigerating parts of the system until it enters the return line of the compressor. During its passage through the units of the refrigerating parts of the apparatus, it expands according to the quantity of heat that it absorbs from the medium with which it is associated. and at the same time discharges the lubricant that has been carried in the refrigerant, gaseous, or liquid, stream. hen the liquefied refrigerant enters the container 7, the lubricant. under the assumption that I have made relative to the densities of the lubricant and the refrigerant liquid, settles to the bottom of the container.

When the container 7 has been charged with the refrigerant liquid, the compressor 1 may cease in its operation and the liquid in the container 7 will evaporate slowly as it absorbs heat from the medium with which it is associated. The vapor passes outward through an opening 24 that is formed in the connector 21. The connector 21 is provided with two pipes 19 and 20 that are located coaxiall v. The pipe 19 is located within the pipe 20 and so as to form an annular chamber 20 between the wall of the tube 19 and the wall of the tube :20. The annular chamber :20 connnunicates with the outlet 24 which is also formed in the connector 21. The lower end of the pipe 1'.) exis also connected to the tube 26 that cone municates with the interior of the container 7 and terminates at the point where a major portion of the lubricant will collect. or separate out from the liquefied refrigerant in the container, that is, the inner end of the tube 26 is preferably located at the bottom of the container 7 if the lubricant has a greater density than the liquefied refrigerant. It may be located at a mid-point, such as, about half the depth of the liquefied refrigerant in the container 7. Also, if the lubricant is soluble in the liquefied refrigerant, the inner end of the pipe 26 may be located at any point below the liquid level.

Since the tube 20 communicates through the connector 25 and the pipe 26, with the interior of the container 7, the liquefied refrigerant will rise in the tube 20 to substantially the level of the liquid in the container 7 when the compressor is at rest. The vapor from the container 7 will pass into the pipe 19 above the level of the liquid in the pipe 19. The pipe 19 is provided with a small opening 30 whose effective cross-sectional area is adjusted by means of the pointed screw 31 which is threaded into the side of the connector 21 at a point opposite the opening 30. If desired, the adjustment may be made when the system is charged with the refrigerant, since the screw 31 fits tightly in the thread formed in the connector 21. The tapped opening is positively closed by means of the gasketed threaded plug 33. The gas evolved from the liquefied refrigerant in the container 7 gradually passes, or seeps, into the top of the pipe 19 with the compressor at rest and as the quantity of heat is absorbed, the pressure of the gas is raised and eventually opens the valve 17 located at the upper endof the pipe 19. The valve is spring pressed by means of the tension spring 18 which is connected to a pin that extends through the pipe 19 and through one end of the spring18. As the pressure below the valve is increased,it will be opened to allow some of the.gas to escape from the container 7 The gas enters thepipe 23 and passes to the bottom of the second evaporating unit which is made in the form of a coil that terminates in a valve controlled outlet similar in form to the valve 17. The valve 39 may be mounted in a suitable housing that is connected to the pipe 37. The valve 39 is also spring pressed by means of the tension spring 41 that is connected at one end to the pin 41 that is located at the lower end of the housing and at the other end to the valve 39.

As the evaporating unit, located intermediate the valves 17 and 39, absorbs heat from the refrigerator in connection with which the apparatus is used, or from any other medium, the pressure within the tube 37 is gradually raised until the fluid within the tube 37 escapes through the valve 39. The suction, produced by the operation of the compressor and acting in the coil 37, to which the compressor is connected through the valve 39, causes an increased attenuation of the vapor in 37 until when the attenuation in '37 becomes great enough the pressure of the gas in the container 7, which is also absorbing heat, the interior of the pipe 37 will receive a new supply of fluid from the container 7 drawn through the valve 17. Owing to the fact that the refrigerant is in the form of a liquid in the container 7 and as such is in very intimate contact with its confining walls, the rate of heat influx from the medium being cooled into the refrigerant per unit of area in the container 7 is considerably greater than what it is in the coil 37 inasmuch as in the coil 37 the fluid is in the form of a mixture of refrigerant liquid and vapor that may be in the form of a foam or froth. This greater heat absorbing efficiency of the cooling surface offered in the container 7 if allowed to operate uncontrolled would tend to lower the effectiveness of the heat absorption in 37 for separating the refrigerant from the lubricant. The valve 17 which regulates the relative pressures between container 7 and coil 37 therefore will be seen to control favorably this relative difference in the heat influx ratios per unit of cooling area in the coil 37 and the container 7. Valve 17 by the yielding resistance placed upon it raises the relative pressure between container 7 and coil 37 making the pressure in 7 controllably greater. as desired, than in coil 37. The corresponding higher temperature at which the liquid refrigerant in 7 is thus maintained enables the heat absorbing effect in 37 to becomeincreasingly varied as desired. The practical result obtained in upsetting this otherwise normal difference in the rate of heat influx existing between container 7 and coil 37 is to assure more positive distillation of the. refrigerant liquid portion of the refrigerant vapor, refrigerant liquid, and lubricant mixture in 37 thus aiding in the desirable and necessary separation of the lubricant from the refrigerant the while confining the refrigerating effect produced by the evaporation of the liquid refrigerant to the refrigerating portion of the system.

Similarly the rate of heat influx per unit of area may be suitably varied between the coil 37 and the cylinder 42, by means of the spring loaded pressure regulating valve 39, thus assuring that the compressor suction will first be more effective in distilling off or evaporating any liquid refrigerant contained in 42 than it is in any of the related parts of the refrigerating system on the coil 37 side of the valve 39. Thus the valves 39 and 17 both help to assure the separation of the liquid refrigerant from the lubricant on the lubricants return circuit to the compressor, by making the compressor suction progressively more effective in evaporating liquid refrigerant the nearer this liquid refrigerant approaches the compressor in its circuit through the various elements of the refrigerating system.

When a material amount of the refrigerant liquid in the container 7 has changed to a vapor, the compressor is automatically started by any of the well known automatic controlling means. When the compressor starts to operate, it draws the vapor from the pipe 44 and produces a lowered pressure in the refrigerating units just referred to. \Vhen the low pressure is transmitted. through the cylinder 42 and the coil 37 to the pipe 19, it draws the vapor from the container 7 through the outlet in the connector 24 and forces the level of the liquid in the annular chamber, formed between the pipes 19 and 20, to the lower end of the pipe 19 and draws the liquid upwards through the pipe 19 and through the valve 17 and into the coil 37, and also it draws the liquid from the container 7 through the pipe 26 which communicates with the lower end of the pipe 20 through the connector 25 which is provided with the passage-ways 26 and 32. The hydrostatic pressure of the liquid will force the liquid through the pipe 26 and tend to position the level of the liquid in the pipe 20 at the same height as the level of the liquid in the container 7, which, however, is caught up by the movement of the vapor through the lower end of the pipe 19 and carried upward through the. pipe 19, past the valve 17, and into the coil 37, through the valve 39 and into the cylinder 42. The rate of flow of the liquid from the container 7 may be regulated by means of-the pointed screw 32 which is adjustahly located with respect to the opening 26. The tapped opening in the connector 25 may also be positively closed by means of the plug 33 similar in form to the gasketed plug located in the connector 21. In this movement of the liquid from the container 7, the

lubricant is also carried and distributed through the parts of the apparatus just described. In order to prevent the passageways from being plugged with any sediment, a screen 27 may be located on the inner end of the pipe 26 so as to cover the outlet of the container 7 through the pipe 26. This sweepin g movement that is produced when the compressor is started, charges the tube 37 with the refrigerant liquid. The vacuous condition created by the compressor in the low pressure side of the system is also sufficiently great to carry the liquid into the cylinder 42, which is so constructed as to retain the liquefied refrigerant until the refrigerant has had opportunity to evaporate.

The cylinder 42 operates as a safety to prevent the movement of a material quantity of the lubricant and liquefied refrigerant to the compressor direct. The cylinder 42 operates to trap the lubricant and liquefied refrigerant and there evaporate the liquefied refrigerant and in the evaporation to progressively separate the lubricant from the liquefied refrigerant. From the cylinder 42 the lubricant is progressively conducted at a uniform rate to the compressor as the compressor continues to operate.

The cylinder 42 is provided with one or more cups 45. The cups 45 form baflies that are adapted to receive and hold the liquefied refrigerant and lubricant so as to prevent their rapid or free movement to the compressor, but while the refrigerant is evaporating the cup, or cups, gradually permit the separation of the lubricant from the liquid and its rcentrance into the vaporized refrigerant. Preferably. the cups are so formed as to provide a passage-way through the cylinder 42 so as to allow the free movem nt of the vapor that may he lelivcred from the end of the pipe 37, and yet so as to catch any liquefied refrigerant that may be drawn in o the cylinder 42. The cups may be provided with conical central openings that w ill catch the liquid and allow its evaporation as the compressor reduces the pressure within the cylinder 42 while, at the same time, the lubricant will he caught by the cups and allowed to gradually descend to the lower end of the cylinder 42. The cups are each provided with small openings 49 which allow the lubricant to leak through each Succeeding cup to the one below and finally into the pipe 4 while the refrigerant liquid in the cups is allowed to evaporate and pass into the pipe 44. The lubricant is thus allowed to enter the pipe 44 and the vapor therein, in small globules or drops and in quantities that are approximately uniform in amount. so that the lubricant will be delivered to the compressor at an aproximately uniform rate and the re- 1 frigerant will be delivered to the compressor in the form of a vapor.

As the compressor operates in drawing low pressure refrigerant vapor from the cooling system described above it compresses the l vapor under high pressure in the condenser coil 3. As the heat from the compressed refrigerant vapor is withdrawn it condenses and passes to the chamber 4. By means of the valve 5, the liquid is periodically and more or less regularly released into the pipe 6 from whence the refrigerant cyclically performs its refrigerating function. Thus the liquid, refrigerant required by the container 7 and its allied parts is automatically replenished.

If it is desired to draw the liquid from the container 7 with the gas discharged from the. container 7 and charge the coil 37 with the desired quantity of liquid by a more direct movement than through the pipe 26, it may be accomplished by the suction that will be produced by a venturi which operates to reduce the pressure at the neck of the venturi. This operation is illustrated in Fig. 3 where the pipe 59 extends to a point below the level of the liquid in the container 7, and terminates in a throat of the venturi 58. When, therefore, the compressor starts it will draw the liquid from the bottom of the container 7, through the pipe 59, in the same manner that the liquid is drawn through the pipe 26. The lower end of the pipe 59 may be covered with a screen 60 to prevent sediment from passing into the system, if desired.

I claim:

1. In a compression refrigerating system, a compressor, a liquefied refrigerant containing reservoir, a lubricant trap consisting of a liquid retainer for retaining mixtures of the liquefied refrigerant and the lubricant, means for permitting the evaporation of the refrigerant, the retainer having outlets for the continuous introduction of the lubricant into the vapor.

2. The process of controlling the return of lubricant to the compressor of a refrigerant apparatus which consists in subdividing pore tions of the mixed liquid refrigerant and lubricant and progressively evaporating the refrigerant of the said subdivided portions and combining the portions of the lubricant as it concentrates in each portion and introducing the lubricant into the compressor.

3. The process of controlling the return of lubricant to the compressor of a refrigerant apparatus which consists in subdividing portrons of the mixed liquid refrigerant and lubricant and progressively evaporating the refrigerant of the said subdivided portions and combining the portions of the lubricant at a substantially uniform rate as it concentrates in each portion and introducing the lubricant into the compressor.

4. The process of controlling the return lubricant to the compressor of a refrigerant apparatus which consists in trapping subdivided portions of the mixed liquid refrigerant and lubricant and progressively evaporating the refrigerant of the said subdivided portions and combining the subdivided portions of the lubricant as it concentrates in each portion of the mixture and introducing the lubricant into the compressor.

5. In a compression refrigerating system, a compressor, a liquefied refrigerant containing reservoir and self-draining liquid trap communicating with the said reservoir for retaining a mixture of the liquefied refrigerant and the lubricant and connected to the compressor for causing the evaporation of the liquefied refrigerant during the concentration of the lubricant, the trap for directing the lubricant in drops into the stream of vapor of the refrigerant.

6. In a compression refrigerating system, a compressor, a liquefied refrigerant container, a heat absorptive unit connected to the container, a release valve for admitting liquefied refrigerant to the heat absorptive unit, a self-draining trap located between the heat absorptive unit and the compressor, and located in the chilling part of the system for trapping liquefied refrigerant and lubricant and separating the liquefied refrigerant from the lubricant and introducing the lubricant in drops into the suction line to the compressor.

7. In a compression refrigerating system, a compressor, a condenser, a liquefied refrigerant containing reservoir, means for releasing the liquid from the condenser and directing the released liquid into the reservoir, the reservoir having a pair of passage-ways leading to the compressor, one communicating with the portion of the reservoir containing the vapor and the other communicating with the portion of the reservoir containing the liquid, the second named passage-way having a smaller cross sectional area at one point to restrict the flow of the liquid, the other passageway having a larger cross sectional area for permitting the movement of a relatively large quantity of the refrigerant vapor drawn from the reservoir by the compressor.

8. In a compression refrigerating system, a compressor, a condenser, an evaporative unit comprising a liquefied refrigerant containing reservoir, means for releasing the liquid from the condenser and directing the released liquid into the reservoir, and means l for causing the flow of either the vapor or the liquid from the reservoir according to marked changes in the pressure in the evaporative unit, the evaporative unit having a heat conductive surface sufiiciently great to evaporate all of the liquid that is transferred from the reservoir, the said reservoir and the said evaporative unit coacting to refrigerate substantially the same medium in the same refrigerating apparatus.

9. The process of automatically controlling the return of lubricant to a compressor in a refrigerating apparatus which consists in subdividing a mixture of the liquid refrigerant and the lubricant into small portions, evaporating the refrigerant from the said small portions, progressively combining the portions to progressively concentrate the lubricant content and directing the lubricant to the compressor.

10. In a refrigerating apparatus, an evaporator for the liquefied refrigerant, means for conducting a mixture of the liquefied refrigerant and the lubricant from the compressor to the evaporator, the evaporator having means for progressively retaining subdivided portions of the liquid refrigerant and the lubricant and separating the lubricant from the li uefied refrigerant by evaporation of the re rigerant to concentrate the lubricant and means for introducing in small subdivisions the lubricant into the said evaporated refrigerant.

11. In a compression refrigeration system, a compressor, a condenser, a releasing valve, a liquefied refrigerant containing reservoir, the releasing valve located intermediate the condenser and reservoir for permitting the liquefied refrigerant to enter the reservoir, means for removing a controlled portion of the lubricant and the liquid refrigerant from the reservoir by the compressor, and means for progressively trapping liquid refrigerant and lubricant as the lubricant increases in concentration and returning the lubricant to the compressor.

12. In a compression refrigerating system, a compressor, a condenser connected to the compressor, a refrigerant evaporative unit, a second evaporative unit for chilling substantially the same medium, means for altering the relative rate of heat influx into one evaporative unit with respect to the other by maintaining a pressure differential between the said units.

13. In a compression refrigeration system, a compressor, a condenser, a releasing valve,

a liquefied refri erant reservoir, the releas-- ing valve locate intermediate the condenser and the reservoir, a second chilling unit communicating with the reservoir and forming a part of the return passage to the compressor and adapted to receive refrigerant fluid from the reservoir, means for supplying the second chilling unit with refrigerant liquid from the reservoir at a measured rate responsive to velocity of flow of refrigerant vapor from the reservoir.

14. In a compression refrigeration system, a compressor, a condenser, a releasing valve, a liquefied refrigerant reservoir, the releas ing valve'located intermediate the condenser and the reservoir for maintaining the quantity of liquid in the reservoir substantially constant, a second chilling unit in series with the reservoir, means for supplying the second unit with refrigerant vapor from the evaporation of refrigerant in the reservoir when the rate of flow of vapor between the reservoir and the second chilling unit is slow,

means for sup lying the'second unit with a mixture of refrigerant vapor and refrigerant liquid at a higher rate of flow between the reservoir and the second chilling unit when the rate of vapor flow between them is high.

15. In a compression refrigeration system, a compressor, a condenser, a releasing valve, a liquefied refrigerant reservoir, the releasing valve located intermediate the condenser and reservoir for permitting the liquefied refrigerant to enter the reservoir, a secondary cooling unit in series with the reservoir, means for spraying controlled amounts of the liquid refrigerant from the reservoir into the secondary unit in accordance with the rate of evaporation in the secondary cooling unit.

16. In a compression refrigerating apparatus, a compressor, a condenser connected to the compressor, a plurality of evaporative units, valves located between the condenser and the evaporative units and between the evaporative units, the valves between the evaporative units operative according to the difference of pressure between the units to provide for periodic movements of the mixed liquid refrigerant and the lubricant to maintaln a substantially uniform return of the lubricant to the compressor.

17. In a refrigerating apparatus, a compressor for circulating the refrigerant liquid and the lubricant that may be deposited therein, a trap for separating the liquid refrigerant from the lubricant and permitting free movement of the refrigerant vapor to the compressor and means for directing the lubricant free from the liquid refrigerant continuously to the refrigerant vapor drawn to the compressor.

18. In a refrigerating apparatus, a compressor for circulating the refrigerant liquid and the lubricant that may be deposited therein, a trap having a plurality of bafiie members for delaying the movement of the liquid refrigerant and the lubricant and permitting free movement of the refrigerant vapor to the compressor and means for directing the lubricant free from the liquid refrigerant continuously to the compressor.

19. In a refrigerating apparatus, a compressor for circulating the refrigerant liquid and the lubricant that may be deposited therein, a trap having a plurality of liquid retainers for receiving in series the liquid refrigerant by overflow of the preceding retainers for delaying the movement of the liquid refrigerant and the lubricant and permltting the free movement of the refrigerantvapor to the compressor and means for directing the lubricant free from the liquid refrigerant continuously to the compressor. v 20. In a refrigerating apparatus, a compressor for circulating the refrigerant liquid and the lubricant that may be deposited therein, a trap having a plurality of liquid retainers for receiving in eries the liquid refrigerant by overflow of the preceding retainers, the retainers having small openings for draining oil concentrate into the succeeding retainer, for delaying tlr movement of the liquid refrigerant run the lubricant and permitting free. movement of the refrigerant vapor to the compressor and means for directing the lubricant free from the liquid refrigerant continuously to the compressor.

21. The process of controlling the return of the lubricant to th compre sor of a refree movement of the refrigerant vapor to v the compressor and means for progressively directing portions of the lubricant free from the liquid refrigerant continuously into the stream of refrigerant vapor drawn to the compressor.

23. A process of controlling the return of lubricant to a compressor in a refrigerating apparatus which consists in separating and concentrating the lubricant from the refrigerant and continuously sub-dividing the separated and concentrated lubricant into drops and directing the drops of lubricant into the evaporated refrigerant notwithstanding changes in rate of the flow of the refrigerant vapor to the compressor.

24. The process of controlling the flow of a mixture of lubricant and refrigerant through the expansion chambers of a refrigerating apparatus having a compressor and a flooded reservoir Which consists in drawing a mixture 'of the lubricant and the liquid refrigerant from the flooded reservoir in amounts that are limited by that which pass an opening under the gravity head of the liquid from the flooded reservoir and evaporating the refrigerant from the mixture and directing the lubricant and the refrigerant gas to the compressor.

25. In a compression refrigerating system, a compressor, a condenser connected to the compressor, a reservoir for liquid refrigerant, a valve located intermediate the reservoir and the condenser, means for directing a mixture of the lubricant and the liquid refrigerant from the reservoir in amounts limited by the amount of liquid that will pass an opening under gravity head and evaporating the refrigerant from the mixture and directing the lubricant and the evaporated refrigerant to the compressor.

26. In a compression refrigerating system, a compressor, a condenser connected tothe compressor, a reservoir for liquid refrigerant a valve located intermediate the reservoir and the condenser. means for directing measured amounts of a mixture of the lubricant and the liquid refrigerant from the reservoir into an evaporative heat absorbent chamber and directing the lubricant and the evaporated refrigerant to the compressor.

In witness whereof I have hereunto signed my name to this specification. I

PHILIP W. DES ROCHES. 

